This application is based on Application No. 2001-222162, filed in Japan on Jul. 23, 2001, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to improvement of a strip joining apparatus in which a back end of a preceding strip and a lead end of a succeeding strip are butt welded or lap welded and then a lead end of the weld location and a lead end of the weld location are notched.
2. Description of the Related Art
In recent years, there have been various improvements of a steel sheet continuous processing apparatus in a steel sheet processing line with an aim to increase productivity, reduce site space, and improve quality stability and yield. Furthermore, in the above strip joining apparatus, one proposition for the processing line has been to drastically shortening a time which the line is stopped when a back end of a preceding strip and a lead end of a succeeding strip are welded and a weld lead end portion and weld lead end portion are notched at an entrance of the steel processing line.
As an apparatus for resolving such a problem, for example, the apparatus disclosed in Japanese Patent Publication Hei 2-38288 may be given. In this apparatus, a welding position and a side notching position are separated a predetermined distance in a traveling direction of the sheet.
That is, after welding, the strip is first moved only a predetermined distance in the traveling direction and then side notching is performed.
FIG. 16 is an explanatory drawing explaining the apparatus disclosed in Japanese Patent Publication Hei 2-38288. The upper portion in FIG. 16 shows the apparatus from above while the lower portion shows the apparatus from the side. As to strips 1, there is a preceding strip la and a succeeding strip 1b. The strips 1 travel in the direction of the arrow C in the drawing. A welding apparatus 35 for welding and a side notching apparatus 36 for side notching are separated in the traveling direction by only a distance L. The side notching apparatus 36 includes a pair of side notching apparatuses 18, 19.
A conventional strip joining apparatus constructed in such a manner entails the following problems. Namely,
a. Because the welding apparatus 35 and side notching apparatus 36 are disposed in tandem in the traveling direction, a long line control period is required to travel the strip to a notching position after it is welded. That is, there is a long period of time from when movement of the strip is haltedxe2x86x92welding is performedxe2x86x92the strip is movedxe2x86x92, until, notching is completed. Generally, when the line is stopped a long time for welding, the system has a major drawback in that a the size of a looper apparatus for storing strips increases. This is because strips are continuously processed even when a strip is stopped and welded at the entrance side. Hence, the looper apparatus must be able to handle an anticipated capacity when a strip is stopped.
b. Since the welding apparatus and the side notching apparatus are disposed separated in the traveling direction, multiple positioning spaces are required.
c. Because the strip is moved from the welding position to a notching position by means of line control, there is a lot of variation in stopping the movement of the strips (normally a variation of xc2x160 mm occurs) and precise notching cannot be performed.
The present invention aims to solve the above problems and an object of the present invention is to provide a strip joining apparatus in which, a time which a line is stopped is shortened, a number of installation spaces is decreased and precise notching is performed.
According to one aspect of the present invention there is provided a strip joining apparatus being a welding system wherein a back end of a preceding strip and a lead end of a succeeding strip are welded while sheet-shaped strips are traveled in a longitudinal direction and both ends of a weld location are side notched after welding, comprising,
a first carriage comprising a shearing means for shearing each of the back end of the preceding strip and the lead end of the succeeding strip in a direction approximately orthogonal to the traveling direction of the strips, a welding means for sequentially welding, along a shearing surface, a location where the back end of the sheared preceding strip and the lead end of the sheared succeeding strip are contacted by abutting or overlapping, and a first side notching means for side notching a weld lead end portion of the weld location provided extending approximately above a weld traveling direction of the weld location, the first carriage provided so as to be capable of moving in the weld traveling direction, and
a second carriage disposed facing the first carriage and comprising a second side notching means for side notching a weld back end portion of the weld location and constituting a pair together with the first side notching means.
According to another aspect of the present invention there is provided a strip joining apparatus being a welding system wherein a back end of a preceding strip and a lead end of a succeeding strip are welded while sheet-shaped strips are traveled in a longitudinal direction and both ends of a weld location are side notched after welding, comprising,
a first carriage comprising a shearing means for shearing each of the back end of the preceding strip and the lead end of the succeeding strip in a direction approximately perpendicular to the traveling direction of the strips, and a first side notching means for side notching a weld lead end portion of the weld location provided extending approximately above a shearing surface of the sheared strip, the first carriage provided so as to be capable of moving in a direction of the shearing surface,
a welding means provided separately from the first carriage and between the shearing means and the first side notching means, for sequentially welding a location where the back end of the sheared preceding strip and the lead end of the sheared succeeding strip are contacted by abutting or overlapping while moving parallel to the shearing surface, and
a second carriage disposed facing the first carriage and comprising a second side notching means for side notching a weld back end portion of the weld location and constituting a pair together with the first side notching means.
According to still another aspect of the present invention the shearing apparatus comprises a punching means for punching said strip concurrently with a shearing operation of said strip at a position separated a predetermined distance from a shearing position.
According to yet another aspect of the present invention, the welding means is laser beam welding.
According to still yet another aspect of the present invention, the welding means is seam welding.
According to still yet another aspect of the present invention, the welding means is arc welding.